Thermal compensation system for the gravitational wave interferometer Advanced Virgo

摘要

In Advanced Virgo, the absorption of a small fraction of the YAG laser power will induce two thermal effects: optical path length distortion in the mirror substrate and thermoeleastic deformation of the mirror high-reflectivity sur-face. These effects can limit the interferometer operation and sensitivity. In order to reduce them, a thermal compensation system must be implemented. The Ad-vanced Virgo system closely follows from that already installed and operating in Virgo. The new system must compensate thermal effects at a level compatible with the Advanced Virgo sensitivity and take into account the need to act on all the Fabry-Perot cavities optics and to monitor their thermal behaviour.